IE8 is
released.It has
four layout modes. To pass Acid2, the new ones make a table
close a paragraph. The parser behavior of <p><table>
is now the only HTML parsing difference between the quirks and
standards modes that is interoperably implemented in all of the top
4 browser engines.

I check
in an implementation of the quirk into the Gecko HTML5 parsing
repository.

May 26th 2009

Hixie checks
in the definition of the quirk into the HTML5 spec. The commit also includes this comment: “i hate myself (this quirk was basically caused by acid2; if i'd realised we could change the specs when i wrote acid2, we could have avoided having any parsing-mode quirks) -Hixie”